The reading of coded information is useful, for example, for the handling of products at a point of sale, in a warehouse, at a collection centre, sorting centre or delivery/distribution point, etc.
Throughout the following description and the following claims, the expression: “reading coded information” is used to indicate the acquisition of information related to an object (for example distance, volume, overall dimensions, or object identification data) for example through the acquisition and processing of a light signal diffused by the same object. In this case the term: “coded information” is used to indicate the whole identification data contained in an optical code.
The term: “optical code” is used to indicate any graphical representation having the function of storing coded information. A particular example of optical code consists of the linear or two-dimensional codes, wherein the information is coded through suitable combinations of elements having a predetermined shape, for example squared, rectangular or hexagonal, of dark colour (usually black) separated by clear elements (spaces, usually white), such as barcodes, stacked codes and two-dimensional codes in general, colour codes, etc. The term “optical code” further comprises, more generally, also other graphical patterns either perceptible or imperceptible to the human eye, with information coding function, including clear printed characters (letters, numbers, etc.) and special patterns (such as stamps, logos, signatures, fingerprints, watermarks etc.). The term “optical code” also comprises graphical representations which are detectable not only in the field of visible light but also in the range of wavelengths comprised between infrared and ultraviolet.
Finally, by “indication of the reading result”, also the mere indication of the end of the reading, or of the unsuccessful reading attempt, is meant.
For the sake of simplicity of description, hereafter explicit reference will be made to optical code readers (commonly called: scanners).
Optical code readers are of various types; they may be based on laser technology (laser scanners) or imaging technology (imager scanners).
Furthermore, optical code readers may be intended for handheld use (portable readers), or to be fixedly resting in a predetermined position (fixed position readers). Fixed position readers are in turn classified as on-counter and in-counter readers, the former being those typically resting on the top of a surface, which is usually the check counter surface, the latter being commonly integrated in the check counter and oriented so that its reading field projects from the check counter surface towards the user or operator.
On-counter readers are also sometimes referred to as “presentation scanners”, due to the fact that the user grabs the object to be identified, typically a good or a document of any type, and moves her/his hand towards the terminal reading face, thus “presenting” the object to be read to it.
In-counter readers are also sometimes called “flatbed scanners”, because the reading window lies flush with the counter surface, or, “vertical scanners” when the reading window lies in a substantially vertical plane facing the operator, or else, “bi-optic scanners” when both configurations—flatbed and vertical—are simultaneously present.
A laser on-counter reader according to the prior art is described in U.S. Pat. No. 6,719,201 and U.S. Pat. No. 7,059,529, and an in-counter retail reader according to the prior art is disclosed in U.S. Pat. No. 8,322,621.
As known, in optical code reading, it is important to give the user a clear and unmistakable feedback of the success/failure of the decoding operation. In fact, the operation of reading a particular optical code can give negative results for various reasons, among which the imperfection of the code due, for example, to damages to the label on which it is obtained, the distance between the reader and the code, or the variation of said distance during the scanning time. In addition, even when the code is correctly acquired, its decoding may result impossible because, for example, it does not fall within the categories of codes recognized by the reader. In any case, the user needs to know whether the code has been decoded before proceeding to read another code.
Simple acoustic, tactile or visual feedback means are already known and currently used for indicating to the user that the particular aimed optical code has been decoded by the reader.
The Applicant realized that the acoustic signal generated by the known acoustic feedback means cannot be easily heard if the operation is carried out in a noisy environment or by an operator with auditory deficiency. Moreover, a frequently repeated acoustic signal may be annoying for the operator who must carry out very frequent readings and/or for a long time interval.
Furthermore, the Applicant noticed that tactile feedback is not suitable for hands free operation.
The Applicant focused its attention to fixed position readers providing a visual feedback of the success/failure of the decoding operation.
It is known to provide a visual feedback by using a light source arranged on the reader body which flashes with green light in case a reading has correctly occurred. In detail, in on-counter and vertical in-counter code readers it is known to position said light source on the upper surface of their body.
FIG. 1 shows by way of an example an on-counter reader 100 according to the prior art provided with a device for visually indicating the reading result which generates a visual indication light 101 appearing on the upper surface 102 of its body 103, with reference to its operating position when installed on a check counter.
The Applicant has considered where the operator focuses his/her attention during operation, based on psychological factors, as described for example in:
“Eye Movements in Reading and Information Processing: 20 Years of Research”, Keith Rayner, University of Massachusetts at Amherst, Psychological Bulletin 1998, Vol. 124, No. 3, 372-422
Walter Gilmore, “The user—computer interface in process control: A human factors engineering handbook”, Elsevier Science, Jan. 1, 1989—Technology & Engineering—456 pages
Bedard P, Proteau L. “Movement planning of video and of manual aiming 30 movements.”, Spat Vis. 2005; 18(3):275-96.
Bedard P, Proteau L., “On the role of static and dynamic visual afferent information in goal-directed aiming movements.”, Exp Brain Res.2001 June; 138(4):419-31.
The Applicant observed that, when bringing an object into the reading field of the reader 100, the visual indication light 101 on the upper surface 102 of the reader body 103 is normally outside of the user's visual cone, whose gaze is usually focused precisely on the object itself and on the reading window 105, namely the opening from which the reading field is projected towards the outside of the reader 100.
In fact, the Applicant observed that, while using fixed position readers, the user's gaze first meets the object to be scanned, and, immediately behind it, the reading window, which is not the primary focus of the user's eye, and so is perceived in its entirety as a background object, while eyes are focused on the object to be scanned, which is generally held with a hand.
More specifically, the Applicant found that the sequence followed by the user's eyes and brain is the following: the user's gaze is first focused at the object being presented to the reading window and the hand holding it; then, the eye attention is transferred towards the reading window in order to mentally draw the desired hand trajectory; thereafter, the hand is moved towards the window in order to reach the position for reading; finally, when reading occurs, the eye visual cone embraces mainly the area delimited by the window surrounding the object.
Thus, according to the Applicant, the zone where visual acuity is maximum is on the object, namely where the brain attention is focused, and the reading window lying behind the object, which is comprised within the peripheral zone of the visual cone. Indeed, the reading window is perceived by the user as a background object which instinctively guides the user's gaze to the position where the object has to be moved.
In view of the above, a visual indication as that provided by the visual indication light 101 on the upper surface 102 of the reader body 103 of FIG. 1, being outside of the user's visual cone, requires a non-spontaneous eye movement in order to be perceived by the user, since the attention of the user is not instinctively captured thereby.
In addition thereto, the user's attention would be captured only if the emitted visual indication light is very bright and this could not occur in an intensively illuminated environment.
Furthermore, the Applicant noticed that the user's line of sight towards the visual indication light 101 can be blocked by the checker keyboard or monitor which are usually placed very close by and above the reader body.
The Applicant thus found that traditional indicator lights placed on top of the reader body are of little help, as they are hidden by the structure where the reader is mounted, or placed at a position the user does not instinctively look at.
For this reason, an indicator light placed on top of the reader body cannot be considered to achieve an effective indication of the success/failure of the decoding operation. This also applies for the area directly above and adjoining the reading window which is generally also covered by the checker keyboard or monitor.
The Applicant realized that in order to achieve an effective visual feedback it is crucial to instinctively capture the attention of the user and that this is obtained when the visual indication is within the user's visual cone and when the visual indication in not obstructed by any object.
Furthermore, in stores where a camera based checkout security system is installed, it is necessary that each checkout security camera of the system reliably detects the visual feedback of the respective fixed position reader in order to check if a read has effectively occurred. This is not assured e.g. in case the indicator lights are placed on top of the reader body since the camera field of view may be blocked by the checker keyboard or monitor.
The Applicant considered the problem of providing a fixed position reader of coded information capable of reliably giving a visual feedback to the user and/or to a checkout security camera of the success/failure of the decoding operation which is immediately perceptible by the user, namely which does not even require a slight movement of the user's eye in order to be perceived, even in those cases when the reader has to be installed in very little space underneath the check counter keyboard or monitor.
The Applicant realized that, when the object is placed at the reading window or passed over the reading window in order to acquire and read the coded information of the object, at least a portion of the reading window or at least some of the areas adjoining laterally the reading window on its left and/or right hand side and/or adjoining the reading window from below are generally freely accessible to the user's sight.